Following genetic footprints out of Africa

A new study, using genetic analysis to look for clues about human migration, suggests that the first modern humans settled in Arabia on their way from the Horn of Africa to the rest of the world.

Led by the University of Leeds and the University of Porto in Portugal, the study is published today in American Journal of Human Genetics and provides intriguing insight into the earliest stages of modern human migration, say the researchers.

"A major unanswered question regarding the dispersal of modern humans around the world concerns the geographical site of the first steps out of Africa," explains Dr Luísa Pereira from the Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP). "One popular model predicts that the early stages of the dispersal took place across the Red Sea to southern Arabia, but direct genetic evidence has been thin on the ground." The international research team, which included colleagues from across Europe, Arabia and North Africa, analysed three of the earliest non-African maternal lineages.

These early branches are associated with the time period when modern humans first successfully moved out of Africa. Using mitochondrial DNA analysis, which traces the female line of descent and is useful for comparing relatedness between different populations, the researchers compared complete genomes from Arabia and the Near East with a database of hundreds more samples from Europe.

They found evidence for an ancient ancestry within Arabia. Professor Martin Richards of the University of Leeds' Faculty of Biological Sciences, said: "The timing and pattern of the migration of early modern humans has been a source of much debate and research. Our new results suggest that Arabia, rather than North Africa or the Near East, was the first staging-post in the spread of modern humans around the world." The research was funded by the Portuguese Foundation for Science and Technology, the Leverhulme Trust, and the DeLaszlo Foundation.

Further information

Paper, titled The Arabian cradle: Mitochondrial relicts of the first steps along the southern route out of Africa is available from Cell Press.